In today's multi-function devices, there is an adjustment feature called “tray alignment” or “paper registration” that allows the user to make an adjustment to the image (vertical or horizontal) position in such a way that the image is centered on the page. This feature can be most helpful when printing in duplex because if the front side is not centered (for example, the left margin is wider than the right margin), then the back side will be printed off center, that is, in the opposite direction where the right margin is wider than the left margin. If, for example, the page is not centered, the front and back side of the printed page will not align.
The tray alignment feature seeks to address this issue. However, even if the tray alignment has been performed, several environmental factors can influence the accuracy of the alignment adjustment.